Police followed the trail of a suspicious green truck and a convicted drug-cooker with links to a missing Calgary boy’s family to a rural Alberta property on the weekend, scouring fields in hopes of solving the weeklong Amber Alert case.

Dozens of police and RCMP officers fanned out across the 16-Hectare property in Airdrie, north of Calgary, searching for anything that could help them find five-year-old Nathan O’Brien and his Grandparents, Alvin and Kathryn Liknes. They disappeared from the Liknes’s Calgary home last Monday.

A public tip led police and RCMP to the rural property in northeast Airdrie at the weekend. A vehicle found on the scene was similar to the description of the Green Ford F150 that was seen driving around the family’s neighbourhood several times on the night the three disappeared.

Police took one man from the residence in for questioning on Saturday, but he was released from custody the following day. Douglas Garland, whose parents own the acreage, remains a “person of interest.”

Garland is in his early 50s. His sister is in a common-law relationship with a member of the Liknes family. Their parents, Archie and Doreen Garland own the property. Land title documents show the family bought the land in 1973.

Police are continuing their search of the property.This weekend’s police search isn’t the first time authorities have descended on the Garland’s farm: in October 1992, police uncovered a drug lab hidden inside a shed on the property.

Although police found no finished product, the lab contained a large quantity of chemicals used to make illegal synthetic drugs like methamphetamine.

Police charged Douglas Garland in connection with the operation, but he disappeared soon after and evaded authorities for seven years.

Authorities found Douglas Garland in 1999, thanks in part to a tipster who contacted police after seeing his picture on an RCMP “most wanted” list online.

Douglas Garland was living in B.C.’s Lower Mainland and working as a chemical mixer at the B.C. Institute of Technology when police found him. He managed to evade detection by stealing the identity of Matthew Kemper Hartley, a 14-year-old boy killed in a car crash in 1980.

Investigators brought in a dog and a police motorboat on Sunday as they shifted their search for a five-year-old Calgary boy and his grandparents to a field and a slough north of an acreage.

The area police were focusing on Sunday is about a kilometre north of the acreage near this Calgary bedroom community that police combed on Saturday.

Yellow police tape blocked off an adjacent road and a half dozen officers and a dog walked through a field to the edge of a large slough. Moments later a Calgary police boat was towed into continue the search while a police helicopter searched overhead.

At Douglas Garland’s trial, court heard he was a genius who studied science at the University of Alberta and studied to be a doctor. He left the program before earning a degree.

He served a 39-month federal prison sentence for drug trafficking.

Douglas Garland’s time on the lam was the subject of a bizarre epilogue years later, when he fought the federal government in court over employment insurance benefits.

Douglas Garland had collected employment insurance benefits after getting fired from Can Test Ltd., a Vancouver laboratory firm where he worked between 1992 and 1997. The government later ruled that his earnings weren’t insurable because he worked under a false identity.

Douglas Garland appealed that decision to the Tax Court of Canada — and won, following a trial where he represented himself.

A written decision by Justice Campbell J. Miller in 2005 said Douglas Garland was a “troubled man,” who had attention deficit disorder and whose exit from university was precipitated by a mental breakdown.

“It was clear he was agitated throughout the trial, but it was also apparent that he was an intelligent individual,” Miller wrote.

The court heard Garland rose to become a supervisor of more than 30 people at Can Test but was unable to cope and suffered another breakdown. He was fired in 1997.

Although Garland concealed his identity, the judge ruled he performed legitimate work and the deceit shouldn’t negate his ability to collect benefits.